#!/usr/bin/env python3
#
# Copyright (C) 2018 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
Parses a input care_map.txt in plain text format; converts it into the proto
buf message; and writes the result to the output file.

"""

import argparse
import logging
import sys

import care_map_pb2


def GenerateCareMapProtoFromLegacyFormat(lines, fingerprint_enabled):
  """Constructs a care map proto message from the lines of the input file."""

  # Expected format of the legacy care_map.txt:
  # system
  # system's care_map ranges
  # [system's fingerprint property id]
  # [system's fingerprint]
  # [vendor]
  # [vendor's care_map ranges]
  # [vendor's fingerprint property id]
  # [vendor's fingerprint]
  # ...

  step = 4 if fingerprint_enabled else 2
  assert len(lines) % step == 0, \
      "line count must be multiple of {}: {}".format(step, len(lines))

  care_map_proto = care_map_pb2.CareMap()
  for index in range(0, len(lines), step):
    info = care_map_proto.partitions.add()
    info.name = lines[index]
    info.ranges = lines[index + 1]
    if fingerprint_enabled:
      info.id = lines[index + 2]
      info.fingerprint = lines[index + 3]
    logging.info("Care map info: name %s, ranges %s, id %s, fingerprint %s",
                 info.name, info.ranges, info.id, info.fingerprint)

  return care_map_proto


def ParseProtoMessage(message, fingerprint_enabled):
  """Parses the care_map proto message and returns its text representation.
  Args:
    message: Care_map in protobuf format.
    fingerprint_enabled: Input protobuf message contains the fields 'id' and
        'fingerprint'.

  Returns:
     A string of the care_map information, similar to the care_map legacy
     format.
  """
  care_map_proto = care_map_pb2.CareMap()
  care_map_proto.MergeFromString(message)

  info_list = []
  for info in care_map_proto.partitions:
    assert info.name, "partition name is required in care_map"
    assert info.ranges, "source range is required in care_map"
    info_list += [info.name, info.ranges]
    if fingerprint_enabled:
      assert info.id, "property id is required in care_map"
      assert info.fingerprint, "fingerprint is required in care_map"
      info_list += [info.id, info.fingerprint]

  return '\n'.join(info_list)


def main(argv):
  parser = argparse.ArgumentParser(
      description=__doc__,
      formatter_class=argparse.RawDescriptionHelpFormatter)
  parser.add_argument("input_care_map",
                      help="Path to the legacy care_map file (or path to"
                           " care_map in protobuf format if --parse_proto is"
                           " specified).")
  parser.add_argument("output_file",
                      help="Path to output file to write the result.")
  parser.add_argument("--no_fingerprint", action="store_false",
                      dest="fingerprint_enabled",
                      help="The 'id' and 'fingerprint' fields are disabled in"
                           " the caremap.")
  parser.add_argument("--parse_proto", "-p", action="store_true",
                      help="Parses the input as proto message, and outputs"
                           " the care_map in plain text.")
  parser.add_argument("--verbose", "-v", action="store_true")

  args = parser.parse_args(argv)

  logging_format = '%(filename)s %(levelname)s: %(message)s'
  logging.basicConfig(level=logging.INFO if args.verbose else logging.WARNING,
                      format=logging_format)

  with open(args.input_care_map, 'rb') as input_care_map:
    content = input_care_map.read()

  if args.parse_proto:
    result = ParseProtoMessage(content, args.fingerprint_enabled).encode()
  else:
    care_map_proto = GenerateCareMapProtoFromLegacyFormat(
        content.decode().rstrip().splitlines(), args.fingerprint_enabled)
    result = care_map_proto.SerializeToString()

  with open(args.output_file, 'wb') as output:
    output.write(result)


if __name__ == '__main__':
  main(sys.argv[1:])